In a typical cellular radio system, wireless terminals (also known as mobile stations and/or user equipments (UEs)) communicate via a radio access network (RAN) to one or more core networks. The wireless terminals can be mobile stations or user equipments (UE) such as mobile telephones (“cellular” telephones) and laptops with wireless capability (e.g., mobile termination), and thus can be, for example, portable, pocket, hand-held, computer-included, or car-mounted mobile devices which communicate voice and/or data via radio access network.
The radio access network (RAN) covers a geographical area which is divided into cell areas, with each cell area being served by a base station, e.g., a radio base station (RBS), which in some networks is also called “NodeB” or “eNodeB”. A cell is a geographical area where radio coverage is provided by the radio base station equipment at a base station site. Each cell is identified by an identity within the local radio area, which is broadcast in the cell. The base stations communicate over the air interface operating on radio frequencies with the user equipments (UE) within range of the base stations.
In some versions (particularly earlier versions) of the radio access network, several base stations are typically connected (e.g., by landlines or microwave) to a radio network controller (RNC). The radio network controller, also sometimes termed a base station controller (BSC), supervises and coordinates various activities of the plural base stations connected thereto. The radio network controllers are typically connected to one or more core networks.
The Universal Mobile Telecommunications System (UMTS) is a third generation mobile communication system, which evolved from the Global System for Mobile Communications (GSM), and is intended to provide improved mobile communication services based on Wideband Code Division Multiple Access (WCDMA) access technology. UTRAN is essentially a radio access network using wideband code division multiple access for user equipments (UEs). The Third Generation Partnership Project (3GPP) has undertaken to evolve further the UTRAN and GSM based radio access network technologies.
Long Term Evolution (LTE) is a variant of a 3GPP radio access technology wherein the radio base station nodes are connected directly to a core network rather than to radio network controller (RNC) nodes. In general, in LTE the functions of a radio network controller (RNC) node are performed by the radio base station nodes. As such, the radio access network (RAN) of an LTE system has an essentially “flat” architecture comprising radio base station nodes without reporting to radio network controller (RNC) nodes.
In LTE the radio network configures the wireless terminal, e.g., the UE, according to the RRC protocol specification (3GPP TS 36.331), incorporated herein by reference. It is up to the network to choose suitable parameter values in order to reach the desired performance, network capacity or coverage. For many of those parameters the network is able to choose a reasonable value without additional information from the UE. For other parameters or decision the UE provides the network with explicit information such as radio measurements which allows the network to decide, e.g., on whether to perform a handover, to configure another transmission mode, or to add a secondary serving cell.
Recently it has been discussed whether the UE shall be allowed/enabled not only to provide measurements, but also to suggest explicit parameter values. UE-provisioned/suggested parameter configurations were supported in earlier versions of the UMTS standard, e.g., for requesting certain QoS handling. But the existing RRC protocol defined in 3GPP TS 36.331 does not allow the UE to suggest or recommend radio parameters to the network. In certain cases (e.g. for the discontinuous reception (DRX) configuration) this may result in inferior performance or too high battery consumption.
Protocols by which the UE could request certain parameter configurations did exist for earlier protocol versions, e.g., in UMTS. However, the drawback of those solutions was that a large number of parameter combinations could be requested, of which most were not supported or at least not properly tested. Even if they were tested, the network had no means to verify that they were allowed/appropriate for this particular UE. Therefore, the concept of a UE requesting parameters to be configured did not work properly and network implementations previously ignored any such requests.